The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of a skilled person in any jurisdiction as at the priority date of the application.
The eye is a complex structure having multiple layers and sub-structures. In order to obtain a diagnosis of certain adverse conditions of the eye, images of one or more layers or sub-structures need to be captured.
Previously, such images were obtained by the use of a monochromatic camera having narrow wavelength coloured paper filters covering an associated light source. However, this arrangement produces deficiencies, namely:                Light passing through a paper filter typically has a variable wavelength reflecting the variations in the surface of the paper filter;        The associated light source is typically brighter than is needed to illuminate the eye; and        As different layers of sub-structures of the eye need to be imaged, time needs to be spent in changing the paper filter.        
It is therefore an object of the present invention to provide an optical arrangement that alleviates some or all of the problems associated with the prior art.